Alright, let's work through 1641 times 3549 step by step
1641 × 3549 = 3549 × (1641)
+ 3549 × 1 giving us 3549
+ 3549 × 40 what gives us 141960
+ 3549 × 600 giving us 2129400
+ 3549 × 1000 yielding 3549000

= 5823909
